Electrical distribution centers are widely used in vehicles. An electrical distribution center can package various fuses, relays and other electrical devices in a central location. Such electrical distribution centers include provisions for electrically connecting a power source and electrical devices housed in the electrical distribution center to electrical wiring harness connectors for supplying power and control signals to various electrical systems of the vehicle. Examples of electrical distribution centers may be found in U.S. Pat. No. 5,715,135 granted to Brussalis et al., U.S. Pat. No. 5,788,529 granted to Borzi et al., and U.S. Pat. No. 7,635,212 granted to Seidler. Electrical distribution centers may also be known as junction boxes, power distribution boxes, electrical centers, and the like.
Currently, electrical distribution centers that incorporate circuit protection devices such as fuses and relays require housings that are made of a high temperature plastic, such as nylon, to resist the heat generated in the high electrical resistance, high current areas. The housings are homogeneous, so the material used in those areas are used for the entire housing. Generally, the high electrical resistance, high current areas are located near relays and fuses and their connecting terminals. The other areas of the plastic are generally exposed to much lower temperatures. There is a higher cost associated with high temperature materials, so the requirements for a few areas, which may typically be about 10% of the plastic volume of the housing, drive a higher cost for the entire housing.